Laboratory glassware refers to a variety of equipment, traditionally made of glass, used for scientific experiments and other work in science, especially in chemistry and biology laboratories. Especially borosilicate glass, pioneered by Otto Schott, or soda lime glass is the preferred glass type for scientific experiments and other work in science, especially in chemistry and biology laboratories. Most laboratory glassware is currently mass produced, but large laboratories may employ a glass blower to construct specialized pieces. When in use, laboratory glassware is often held in place with clamps made for that purpose, which are likewise attached and held in place by stands or racks. Describing glassware can be complicated since manufacturers provide conflicting names for glassware. Laboratory glassware may be part of a sophisticated apparatus, as is the case with certain types of condensers, and it may be used in conjunction with other laboratory equipment such as ring stands, burette clamps, and Bunsen burners.